The present invention relates to a device for directing optical rays comprising at least one deflecting mirror and a ray exit member adjoining it, said member being able to be pivoted around two axes which are perpendicular to each other, one pivot axis being parallel to the ray incident to the mirror or coinciding with such ray and the second pivot axis being perpendicular thereto.
Devices of this type serve to direct a ray along given areas of a component, more especially for machining workpieces with laser rays, as for example in welding, hardening, cutting etc. The device is then so arranged in relation to a machining table that relative motion in three dimensions is possible between the device and the table.
The German patent No. 3,530,189 describes a device of this type which has a number of articulated arms each provided with a deflecting mirror. Each articulated arm is able to be turned about an axis which coincides with the respective incident ray so that the last link serving as the ray exit member, and therefore the output ray, is able to be pivoted in one direction. The focal point of the emerging ray may then describe a circle or be moved along a tangent thereto. In a welding operation, for example, the weld seam is produced under the emerging ray perpendicular to the direction of pivoting. A correction in position is carried out with the pivoting motion of the ray exit member.
This procedure is used for machining flat workpieces. If a curved piece of work is to be welded or cut, the holding means is then so pivoted together with the component that the ray is always perpendicular to the unit of surface on which the ray is incident. This requires complex mechanisms, which in addition to the linear motion in one plane also involve pivoting motion either of the work table or of the ray directing mechanism. Furthermore it is no longer possible to ensure a precise control of the ray's point of incidence.